1. Field of the Invention
The present invention relates to an electromagnetic device that converts sounds and mechanical vibrations from a musical instrument into an electrical signal. In particular, the pickup system of the present invention includes a cartridge to enhance conversion of an input from the musical instrument to the electrical signal.
2.Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
The pickup known in the prior art normally includes a transducer, a permanent magnet wrapped with thousands of turns of wire. The magnet and coil of wire are mounted on the body of the instrument. The location varies, depending upon the features of each instrument. The pickup can be attached to the bridge, neck, pickguard, sound hole, etc. A vibration of the instrument interacts with the magnetic field of the transducer so as to induce an alternating current through the coil of wire. This electrical signal travels by cable for amplification, broadcasting, or recording or other use. The general and well established concept is formation of a magnetic circuit, wherein magnetic flux through the transducer is caused by input from the musical instrument. The basic induction of current is moving the coil around the magnet, wherein vibration of the coil around the magnet generates current through the wire. Vibration pickups rely upon this magnetic flux of the magnet by physical vibration of the coil. Sensitivity of the coil vibrations detect different sound vibrations, which affects the signal generation and quality of sound picked up through the system.
Another prominent conventional pickup system is a magnetic pickup, in which the movement of magnetic instrument strings through the magnetic field of a transducer causes a disruption of the magnetic field of the transducer. A variable current flows in the coil windings corresponding to that disruption of the magnetic field, which represents the sound of the string movement. More particularly, a transducer for converting between magnetic field disruptions and electrical signal can convert the magnetic string movements into a pattern of variations in the electrical signal.
The other prominent conventional pickup system is a piezoelectric pickup, in which pressure variations in the form of sound act on two opposing faces of a piezoelectric element to generate electric charge within the piezoelectric element. The piezoelectric pickups are typically used for acoustic guitars and stringed instruments with a bridge, like the cello and violin. The placement on the bridge is recommended because stronger vibrations occur at the bridge. The transduction of sound into an electrical signal does not rely upon the magnetic field of the transducer. It is also possible for hybrid pickups to include any combination of vibration, magnetic and piezoelectric systems.
In the past, various U.S. patents have been granted in the field of pickup devices. For example, U.S. Pat. No. 3,624,264 issued to Lazarus on Nov. 30, 1971 teaches a vibration transducer for detecting vibrations in general and sound from a musical instrument. The invention shows three piezoelectric vibration detectors oriented to detect vibrations along all three orthogonal axes established by walls of a sealed chamber.
U.S. Pat. No. 5,276,276 issued to Gunn on Jan. 4, 1994 discloses a coil transducer, relying upon the vibration of a coil around a magnet to induce current. In the invention, a pair of coils directly connects to the resonating surface of a musical instrument. The vibration of coils correlates to the resonating surface in the vicinity of a magnet.
U.S. Pat. No. 5,898,121 issued to Riboloff on Apr. 27, 1999 discloses an electrical musical instrument pickup system including switchable series-connected hum-canceling windings. There is a single-coil magnetic pickup mounted on the guitar beneath strings of the guitar including a single coil windings and magnets, and a second single-coil magnetic pickup mounted beneath the strings of the guitar with magnets oriented in opposite alignment to the first pickup's magnets in what is known as a ‘humbucking’ or ‘hum canceling’ arrangement. The invention presented a solution to the extra vibrations being picked up by the transducer, and a switch allows a dampening of the extraneous hum sound.
U.S. Pat. No. 5,925,839 issued to Schertler on Jul. 20, 1999 teaches a bridge with a piezoelectric pickup. The piezoelectric pickup can be used with acoustic instruments without feedback problems or interference from magnetic fields of other devices. The '839 patent discloses an air chamber adjacent to the transducer.
U.S. Pat. No. 5,641,932 issued to Lace on Jun. 24, 1997 discloses a sensor assembly for stringed musical instruments. The invention addresses the problems of a vibration piezoelectric pickup with non-magnetic instrument strings. The strings are not equidistant to the piezoelectric sensor, so that distortion occurs. The present invention uses a resonator plate for a refined sound. The resonator plate is also compatible with electric guitars in a hybrid system.
There are also a series of patents by Hosler (U.S. Pat. No. 7,132,597 issued on Nov. 7, 2006;U.S. Pat. No. 7,291,780 issued on Nov. 6, 2007;and U.S. Pat. No. 7,667,128 issued on Feb. 23, 2010) teaching transducers for converting between mechanical vibration and electrical signal. The '597 patent discloses a transducer with a magnet and coil in a housing filled with damping fluid. The magnet and coil vibrate relative to each other. The '780 patent claims a transducer with a magnet in side-to-side polar orientation and restricted linear and rotational movement through the coil. The housing may also be filled with fluid. The '128 patent shows another transducer with the magnet and any electrical signal carrier connected and vibrating relative to each other in a housing filled with fluid. The patents disclose variations of magnet types and electrical signal carrier types vibrating in a housing filled with damping fluid.
The prior art pickup systems each have particular drawbacks which impact the sound quality transmitted by the instrument. The magnetic pickup requires ferromagnetic strings. Strings fabricated from synthetic or organic materials are not magnetically susceptible and, therefore, do not affect the magnetic field. The sound qualities of non-ferromagnetic strings are not compatible with the magnetic pickups. Other qualities of the string movement are also not detectable by the magnetic field created by these electromagnetic sensors, such as the sound waves directly produced by the movement of the strings through the air.
Vibration pickups are limited in range by placement. String sensing transducers have traditionally given a fair representation of sound; however, they are limited in range to string movement alone. Sound from subtle vibrations in the instrument's body materials, shape of the instrument cavity or other important aspects of the instrument sound, are not detected, when the vibration pickup is not physically close enough. Vibration pickups, attached at different locations to the instrument's body or soundboard, are susceptible to dampening, which results from the musician simply holding the instrument or gripping the instrument. Piezoelectric pickups suffer from the same problem of proximity to the sound source, and they also tend to produce an unattractive sound distortion that can be especially problematic when amplified.
In any prior art system, there is no pickup capable of transducing ferromagnetic string movements through a magnetic field, vibrations from the body of the instrument, sound waves produced by the moving strings and sound waves projected from the sound hole or body of the instrument. Each prior art pickup contains permanent components, such as a permanent magnet, coils, cylindrical housing, damping fluid, etc. The permanent structures produce a known sound quality from the musical instrument, even if such sound quality is an incomplete profile of the musical instrument. A magnetic pickup with ferromagnetic strings will only produce electric signals from those strings, so vibration of the instrument body will not affect those electric signals. The operator can compensate for this feature of the pickup system attached to the particular instrument.
If a more complete profile or a different profile of the instrument is desired, then the pickup system must be changed to transduce more or different sound characteristics beyond the limitation of the particular pickup only. At this time, there is no pickup system to allow such changes to the pickups. All prior art pickup systems are fixed, requiring expertise for removal and installation. A switch from a magnetic pickup to a piezoelectric pickup requires the instrument to be disassembled and re-assembled. The placement of the piezoelectric pickup is different from the magnetic pickup because of the need for proximity to the mechanical vibration. There is a need for a pickup system with an easier exchange of pickups for an easier adjustment of desired sound quality from the instrument.
It is an object of the present invention to provide a pickup system that responds directly to ferrous string movement through a magnetic field, mechanical vibration from the body of the instrument, sound waves due to string movement through the air near the pickup and vibrations from sound waves emitted from the body of the instrument.
It is an object of the present invention to provide a pickup system to transduce sound waves and vibrations caused by string movement and mechanical vibration from the body of the instrument, when the strings are not ferromagnetic.
It is another object of the present invention to provide a pickup system with a vibrational pickup placed in close proximity to the instrument strings in order to transduce string movement into the electrical signal.
It is another object of the present invention to provide a pickup system with an induced magnetic field component, being responsive to variations in ferrous string movements, wherein the mechanical vibrations due to body resonance, sound waves from the moving strings and even sound waves emitted from the body of the instrument each affect and slightly alter the variable magnetic field.
It is still another object of the present invention to provide a pickup system with compatibility to transduce tones of different materials according to individual preferences.
It is still another object of the present invention to provide a pickup system to enhance selection of a sound profile or perceived sound of an instrument by applying different resonant materials with respective sound quality characteristics.
It is another object of the present invention to provide a pickup system with an induced magnetic field component, wherein mechanical vibrations due to resonance of the material of the cartridge or container affect the variable magnetic field.
It is still another objection of the present invention to provide a pickup system to convert resonance properties from particular materials into effects detectable by a magnetic field.
It is an object of the present invention to provide a pickup system with a cartridge means which can be removably attached. Each cartridge is comprised of a container with a different effect on the electrical signals transmitted from the instrument. The container can also be removably attached to the cartridge means.
It is an object of the present invention to provide a pickup system with a cartridge means having an induced magnetic field to affect the perceived sound of the instrument.
It is an object of the present invention to provide a pickup system with a cartridge means having a container filled with a ferromagnetic fluid to induce a magnetic field to affect perceived sound of the instrument.
It is an object of the present invention to provide a pickup system with a cartridge means having a container filled with a ferromagnetic fluid and made of a resonant material to affect perceived sound of the instrument.
It is another object of the present invention to provide a pickup system with a cartridge means which is easily replaced and interchangeable.
It is another object of the present invention to provide a pickup system with a cartridge means with interchangeable containers.
It is still another object of the present invention to provide a pickup system with a cartridge means which can be removably attached and de-tached without any disassembly of the instrument.
It is still another object of the present invention to provide a pickup system which can easily change the perceived sound of the instrument.
These and other objectives and advantages of the present invention will become apparent from a reading of the attached specifications and appended claims.